Primary Amoebic Meningoencephalitis (PAM)

Primary Amoebic Meningoencephalitis (PAM) is a rare and often fatal brain infection caused by the amoeba Naegleria fowleri. The infection occurs when the amoeba enters the body through the nasal passages, typically while swimming in contaminated water, and migrates to the brain via the olfactory nerve.

Symptoms

• Initial symptoms may include:
  • Headache
  • Fever
  • Nausea and vomiting
  • Stiff neck
  • Confusion and disorientation
• As the infection progresses, symptoms may worsen to include:
  • Seizures
  • Coma
  • Respiratory failure
  • Cardiac arrest

Causes and Risk Factors

The primary cause of PAM is the presence of Naegleria fowleri in contaminated water. The amoeba thrives in warm, freshwater environments, such as:

• Lakes
• Rivers
• Hot springs
• Swimming pools with inadequate chlorination

Risk factors for PAM include:

• Swimming in contaminated water, especially during warm weather months
• Participating in water sports or activities that involve submerging the head underwater
• Having a compromised immune system

Treatments

Treatment for PAM typically involves a combination of medications and supportive care. The primary goal is to eliminate the amoeba from the body and manage symptoms.

• Medications:
  • Amphotericin B: an antifungal medication that is also effective against Naegleria fowleri
  • Miltefosine: an antiprotozoal medication that has shown promise in treating PAM
  • Flucytosine: an antiviral medication that may be used in combination with other treatments
• Supportive care:
  • Intensive care unit (ICU) admission for close monitoring and management of symptoms
  • Respiratory support, such as mechanical ventilation
  • Cardiac support, such as medication to manage blood pressure and heart rate
  • Seizure control, using anticonvulsant medications

Prevention

To reduce the risk of PAM, it is essential to take precautions when swimming in freshwater environments:

• Avoid swimming in areas with known Naegleria fowleri contamination
• Use nose clips or hold your nose shut while swimming in potentially contaminated water
• Avoid submerging your head underwater, especially during warm weather months
• Ensure that swimming pools are properly chlorinated and maintained

Prognosis

The prognosis for PAM is generally poor, with a mortality rate of approximately 95%. Prompt medical attention and aggressive treatment may improve outcomes, but the infection often progresses rapidly, making timely intervention crucial.